Which sentence is grammatically correct?

As per your request, I have enclosed herewith the additional copy of the handover document for the project completed last week.

As per your request, I have enclosed herewith a second copy of the handover document for the project completed last week.

Please advise me if there is any difference between second copy and additional copy. We have already submitted a handover document to the client. They are now requesting one more copy of the document. Which word will suit in this sentence.